Eccentric wheel accumulators

ABSTRACT

This is an improvement in an accumulator conveyor of the type in which the application and release of the propelling force is effected through changes in the vertical positioning of a propelling member supported on rollers having a flattened portion. A particular feature of the invention is the provision of pairs of coaxially adjacent rollers, eccentric in cross section and rotatable relative each other between a stationary dwell position when positions of least radius are in phase with each other and a drive position wherein portions of least radius are out of phase with each other. In the drive position, the rollers rotate jointly together in out of phase relationship, forming a circular roller maintaining support for the propelling member at a constant vertical position.

United States Patent [191 Bowman ECCENTRIC WHEEL ACCUMULATORS [75] Inventor: Clyde L. Bowman, Grand Rapids,

Mich,

[73] Assignee: Rapistan Incorporated, Grand Rapids, Mich.

[22] Filed: June 27, 1973 [21] Appl. N0.: 373,928

[52] US. Cl 198/184, 198/127, 226/154 Primary Examiner-Richard A. Schacher Assistant Examiner-Richard K. Thomson Attorney, Agent, or FirmPrice, Heneveld, Huizenga & Cooper 5 7 1 ABSTRACT This is an improvement in an accumulator conveyor of the type in which the application and release of the propelling force is effected through changes in the vertical positioning of a propelling member supported on rollers having a flattened portion. A particular feature of the invention is the provision of pairs of coaxially adjacent rollers, eccentric in cross section and rotatable relative each other between a stationary dwell position when positions of least radius are in phase with each other and a drive position wherein portions of least radius are out of phase with each other. In the 'drive position, the rollers rotate jointly together in out of phase relationship, forming a circular roller maintaining support for the propelling member at a constant vertical position.

26 Claims, 12 Drawing Figures PATENIELDECI'IIBH 3,854,576

sum 10F 3 4a 0 Q di PATENIEB 0521 71974 sum 2 or 3v I "BM N255 ECCENTRIC WHEEL ACCUMULATORS BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to powered conveyors of the wheel, roller and, belt variety wherein a propelling member is raised or lowered into a drive or dwell position. More particularly, this invention relates to a novel eccentric cam roller means utilized to raise and lower the propelling member.

II. Description of the Prior Art Accumulators of the type which this application relates to generally are described in detail in US. Pat. No. 3,420,356 entitled ACCUMULATOR CON- VEYOR WITH PNEUMATIC DELAY issued Jan. 7, 1969 to M. J. De Good, et al., and US. Pat. No. 3,253,697 entitled VARIABLE PRESSURE CON- VEYOR issued May 31, 1966 to M. J. De Good, et al. In these patents, an eccentric cam with a flat portion lifts or lowers a propelling member for selective drive or accumulation. This type of operation is equally applicable to conveyors of the powered roller type and those in which the belt is at the conveying surface as illustrated in US. Pat. No. 3,253,697.

A principal drawback to known types of eccentric cams of the prior art is that the eccentric rollers produce a constant vertical reciprocation of the propelling member resulting in rapid, alternate drive and release of each drive roller or the articles to lower the propelling member. Thus, in article driving phase the driving force is delivered to the articles in pulses.

The pulsing is especially critical when the propelling member makes direct contact with the articles. Here the pulsing is directly translated to the articles or cartons being conveyed. With the trend in the United States toward the utilization of lightweight or so-called flimsy containers for ecological reasons, advanced deterioation or breakage of the packages or articles therein can occur as a result of this vibratory or pulse form of propulsion.

An additional significant drawback of the devices of the prior art is the noise level caused by the constant intermittent engagement between the eccentric cam rollers and the propelling member during the drive or raised operation. Noise levels in industrial environments have recently attracted considerable attention for health and environmental reasons. Thus, there is a need in this art for an improved conveyor operation which operates at lower noise levels than presently provided.

SUMMARY OF THE INVENTION In accordance with the invention, a novel cam roller means is provided for supporting a continuous propelling member in both raised (drive) and lowered (accumulation) positions. The cam roller of this invention includes a pair of coaxially adjacent rollers, each eccentric in cross section and having restricted rotatability relative each other. In the accumulation phase, the portions of least radius of both rollers are held stationary in phase with each other and in the drive phase or position the portions of least radius rotate out of phase with each other. The rollers in the drive position or phase rotate together and jointly form a circular roller supporting the propelling member at a constant height. While in the accumulating (dwell) position, the portions of least radius are in phase and upwardly facing so that the propelling member is lowered. A keeper is movable into engagement with a stop on each cam roller'means to hold the roller means in the dwell position. Subsequent release permits the rollers, under the influ ence of the propelling member, to shift into drive position, out of phase.

The preferred propelling member is a belt, the upper surface of which can be utilized to drive appropriate rollers or wheels on which the articles or cartons are supported or in the alternative, the articles can be engaged directly on the belt.

A significant advantage of the present invention is a roller which is circular in drive phase and lifts the belt into a constant drive position. Supporting the propelling member at a constant height eliminates fluctuation of propelling member height; eliminates pulsation in conveyor operation and significantly reduces associated noise levels. While the cam roller means is primar ily utilized for accumulation conveyors, its use is envisioned in other types of environments.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation view of the split-cam roller of the invention illustrated in the dwell or accumulation phase;

FIG. 2 is a side elevation view taken in cross section along the plane 22 in FIG. 1;

FIG. 3 is a cross-sectional view of the split-cam roller taken along the plane 33 in FIG. 1;

FIG. 4 is a front elevation view of the splitcam roller of the invention illustrated in the raised or drive positron; 7

FIG. 5 is a side elevation view taken in cross section along plane 5-5 of FIG. 4;

FIG. 6 is a cross section view taken along plane 6-6 of FIG. 4;

FIG. 7 is a fragmentary schematic plan view of a roller conveyor incorporating this invention;

FIG. 8 is a fragmentary elevation view in cross section taken along the plane VIII--VIII of FIG. 7;

FIG. 9 is a fragmentary sectional view taken along the plane IX--IX of FIG. 8;

FIG. 10 is a perspective view of an alternative conveyor arrangement incorporating this invention;

FIG. 11 is a fragmentary elevation view in cross section illustrating the invention in the conveyor of FIG. 10; and

FIG. 12 is a sectional view taken along plane XII- XII of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawings and particu- Early, FIGS. 1 and 4, each split-cam roller 10 is comprised of an inner roller 12 and a pair of outer rollers 14 and 16 rotatably mounted on a conveyor axle 18. The inner roller has a pair of spaced roller units 12a and 12b joined together by a tubular hub 120. In the preferred embodiment, the rollers are metal and each roller includes a roller bearing assembly (not shown).-

The rollers are eccentric as will be described hereinafter and outer rollers 14 and 16 are rotatable relative to and jointly with roller 12 between a first position defined as the dwell or accumulating phase illustrated in FIGS. 1-3 and a raised drive position illustrated in FIGS. 4-6. In the accumulation phase, the flattened portions or portions of least radius 44, 46a and 4612 are held stationary in phase or alignment so that a propelling member such as a belt 50 drawn over the rollers (FIGS. 1-3 is in a lowered position out of engagement with the article or article supporting rollers. In the drive phase (FIGS. 4-6),.the portions of least radius 44 of the outer rollers are rotated and held approximately 180 out of phase with the portions of least radius 46a, 46b of roller 12 so that the belt or propelling member 50 is raised a constant vertical distance causing article movement. The rollers 12, 14 and 16 in this position rotate jointly as a circular roller.

Referring to FIGS. 1 and 2, each outer roller 14 includes a circumferential rim or flange 20 and web 22, the latter interconnecting flange 20 to the pulley hub 24. The roller is also strengthened and braced by a plurality of ribs 26 integrally connected with the flange, web and hub. Roller 16 is identical to roller 14 and is similarly constructed,'the details not being illustrated.

Roller unit 12a of split roller 12 likewise has a circumferential flange or rim portion 26a (FIGS. 1, 3 and 6) interconnected to a hub 28a by web 30a. Radially extending ribs 32a strengthen and support the integral elements of roller unit 12a. Roller unit 12b is identical to 12a and thus not described in detail. The suffix b is utilized to illustrate corresponding elements as shown in the drawings.

Outer rollers 14 and 16 are rotatable relative to each other and inner roller 12. Their relative rotation, however, is restricted through a revolution slightly less than 180. A stop pin 36 is anchored longitudinally through inner roller 12 parallel to the axis of axle 18 and spaced radially approximately midway between hub 12c and outer raceways 26a and 26b. The significance of the spacing will be described subsequently hereinafter. The length of stop pin 36 exceeds the longitudinal thickness of roller 12 such that one end 38 extends through web portion 22 of roller 14 while the other end 40 extends through the web portion of roller 16. The means permitting extension through the appropriate web portions of rollers 14 and 16 is provided by a lost motion catch in the form of a circumferential slot 42 (FIGS. 2 and Slot 42 extends approximately 180 thus preventing rotation of outer rollers 14 and 16 relative each other and inner roller 12 by the same degree of revolution.

Each of rollers 12, 14 and 16 is circular except that each is eccentric having a flattened portion of least radius. Rollers 14 and 16 have a portion of least radius 44 while roller units 12a, 12b have portions of least radius 46a, 46b. Rollers 14 and 16 are identical to each other such that when stop pin 36 is in abutment with either respective end of slot 42 of each roller, they are in complete alignment and their portions of least radius (FIGS. l-3) which is generally in the form of a belt continuously moved across the flange or rim surfaces of each roller, more specifically, flanged surfaces of rollers 14 and 16 and flanged surfaces 26a, 26b of roller units 12a, 12b. The belt 50 preferably includes a depending central portion 52 which fits loosely within the circumferential slot or groove 54 formed by spaced roller units 12a, 12b and hub 120 as illustrated in FIG. 1. The weight and friction of propelling member 50 when pulled across and in contact with rollers 12, 14 and 16 urges rotation of the rollers,

Except for transitional movement, each split-cam roller 10 is positioned in either a raised-drive position or lowered-accumulating (dwell) position which positions are illustrated in FIGS. l-6. Referring now in particular to FIGS. 1-3, split-cam roller 10 is illustrated in what would be referred to as the accumulating position wherein if the propelling member 50 were being pulled across the upper surface from left to right in FIG. 2 (See arrow C), rotation of the rollers would be urged in the clockwise direction. If a physical stop (such as 114) were positioned in front of stop pin 36 in the position illustrated in FIGS. 1 and 2, further rotation of roller 12 would be prevented and, depending on the relative position of rollers 14 and 16, they would cease rotating within approximately one-half a revolution when stop pin 36 reached one end of slots 42. In this position, the portions of least radius 44 and 46a, 46b are all positioned upwardly in phase so that the propelling belt 50 being pulled there across is in effect lowered. The rollers in the dwell position are brought into a stationary state and will remain so until the stop is removed from interference with stop pin 36.

The alternative position of operation of split-cam roller 10 is illustrated in FIGS. 4-6. Once the physical stop (not shown) is removed from interference with stop pin 36, the particular propelling member being moved across the portions of least radius of the rollers will cause immediate rotation of the inner split roller 12. The reason for this is the greater magnitude of the portions of least radius 46a, 46b relative to portions 44 of the outer rollers as illustrated in FIGS. 1 and 2. In the accumulating or dwell position, the belt such as belt 50 will actually become disengaged from the portions of least radius 44 so that when the physical stop is removed, inner roller 12 will begin rotating immediately. Inner roller 12 in fact will rotate through the complete circumferential length of slot 42 since as it begins to rotate, its radius increases as the portion of least radius rotates out of contact with the propelling member. Upon reaching the opposite limit of slot 42 however, pin 36 will engage the end of each slot in rollers 14 and 16 causing them to rotate jointly with roller 12 approximately out of phase. In this out of phase position, the portions of least radius 44 and 46a, 46b are out of phase with each other thereby combining to form an effective roller having a circular cross section (FIGS. 5 and 6) when the outer rollers and inner roller are out of phase with each other. This out of phase operation will lift the propelling member moving across the outer surfaces of the rollers and rollers 12 and 14, 16, in combination, will provide a belt supporting roller of uniform radius, the belt being positioned for propelling articles along the conveyor causing a drive function as will be described shortly hereinafter.

Referring briefly to FIG. 2, outer rollers 14 and 16 8 preferably include a counterweight 60 which urges the portion of least radius 44 into an upper orientation when the roller is not under the influence of an outside force, such as engagement with belt 50. Obviously, the frictional effect of the propelling member pulled across the outer surface of each roller will overcome the counterweight bias. However, when the split-cam roller pin is stopped in the dwell or accumulating phase, even though the propelling belt is lifted off the surface of portions of least radius 44 of each outer roller, the bias weight will tend to rotate the outer rollers slightly towards the upstream transition portion 52 (FIG. 2) of each outer roller which will come into contact with the propelling member 50 so that constant reciprocating pulses are not being effected. This greatly reduces the clatter around the conveyor unit itself. Also, during joint rotation when belt 50 is contacting roller 12 (FIGS. 5 and 6) counterweights 60 will bias roller 14 and 16 out of engagement with belt 50 until pin 36 drives it around. Thus, during rotation there is a natural out of phase binary.

Referring to FIG. 3, inner roller 12 and its roller units 12a, 12b likewise include a counterweight 64 positioned so that the portion of least radius 46a and 46b is rotated away from the upper dwell position in a direction opposite the urgency of rotation of outer rollers 14 and 16. This will ensure contact between the flanged surface 46a, 46b of inner roller 12 at all times with the propelling member being moved there across. This is of significance during startup also since it could be that the belt might under certain circumstances be spaced from the portions of least radius of each roller when the belt is stopped. However, the urgency of counterweight 64 will ensure that the inner roller 12 will always engage the propelling member so that during startup, positive engagement exists between the actuating portion (inner roller 12) of each split-cam roller. Also, when rollers 14 and 16 are in drive contact with belt 50, weights 64 urge roller 12 out of phase with rollers 14 and 16 in the same fashion as described above in regard to rollers 14 and 16. In view of the foregoing detailed description of the unique cam-roller 10, its operation within one or more particular types of conveyor environments should be obvious.

Referring specifically now to FIGS. 79, the numeral 100 indicates a roller conveyor having conventional side frame members 102 and 104 between which extend a plurality of driven or propelling rollers 106. The rollers 106 are arranged in spaced relationship along the conveyor and in a common plane to form a conveying surface. Beneath the rollers 106 is a driven propelling member 50a moved by any suitable power means in the direction of the arrow A of FIG. 8, thus rotating the rollers 106 to move articles in the direction of the arrow B. At suitable intervals, the side frame members 102 and 104 are connected by rigid cross braces 108.

The upper run of propelling member 50 is supported on the split-cam rollers 10. These rollers are placed at equal intervals along the length of the conveyor, only one of which is shown in phantom in FIG. 7. Where the propelling member is a belt having a depending central tracking ridge 52a (FIG. 9), these rollers are of sufficient width to support a substantial lateral portion of the propelling member and are equipped with a central circumferential channel 54 formed by the spaced inner roller units 12a, 12b as described previously.

As described previously, stop pin 36 is anchored within inner rollers 12a, 12b and rotates therewith within channel 54. A stop means or looking slide 112 (FIG. 8) is slidably seated beneath split-cam rollers and includes upstanding stop portions 114 which are positioned in alignment with and for cooperative association with channel 54 and stop pin 36. A plurality of slides 112, 112a, etc., are arranged longitudinally endto-end the length of the conveyor.

Each locking slide 112 is common to several of the cam rollers 10, the number being determined by the size of the articles to be conveyed. Thus, it might in clude three, four or even fifteen or twenty of the cam rollers 10. In the particular construction illustrated, each slide cooperates with four of the cam rollers 10 defined in zones I, II and III (FIG. 8). The length of the slide will be determined by the length of the zone which is determined to be suitable for change in belt attitude for each article as it passes along the conveyor.

Each locking slide 112 has an upstanding stop, 114 for each of the cam rollers 10. These stops cooperate with stop pins 36 so that when the locking slide is in a active or interfering position (FIG. 9), the stops are so located as to interfere with stop pin 36 to prevent free rotation of the particular associated split-cam roller 10. When the slide is shifted longitudinally (slides 112 and 112b, FIG. 8) out of interference, the associated stops are removed from interference with the associated stop pins 36 and the associated split-cam rollers 10 are free to rotate.

Each locking slide 112 is secured to a pair of rocker arms 116 (FIG. 8) extending downwardly from each side of a sensing roller 118. A rod 120 interconnects the lower ends of each rocker arm 116, slide 112 being anchored to the center portion of each rod 120 (FIG. 8).

The rocker arms are pivotal about a shaft 122 while the lower ends of the arms are attached to springs 124 which bias the sensing roller 118 upwardly and the associated locking slide 112 forwardly so that stops 114 are in a non-engaging position. As will be seen in FIG. 8, sensing rollers 118, in normal position, are raised slightly above the plane of the conveying surface of the conveyor. Thus, as an article D passes over them, they are depressed as indicated by the roller 1 18. This pivots the assembly to shift stop slide 112a rearwardly for interference with stop pins 36 of the four split-cam rollers 10 associated with the particular stop slide. Articles supported by the associated conveyor rollers 106 will thus stop since belt a is lowered out of. engagement therewith. Preferably, the sensor of one zone actuates the slide of the adjacent upstream zone. Thus, as depicted in FIG. 8, sensor 118 in zone I actuates slide 112a in zone II, the operation of which is well-known to one skilled in the art.

FIG. 9 clearly illustrates one of the stops 114 in interference with stop pin 36 causing the split-cam roller 10 to be held in a stationary position as illustrated and described in detail with regard to FIGS. 13. In this position, belt 50a is lowered out of engagement with the roller 106 immediately thereabove causing the articles under the influence of the particular group of rollers 106 being stopped to come to rest.

Thus, in light of the foregoing, the basic operation of conveyor is described wherein various sections of the conveyor are operational between a drive phase when belt 520 is vertically raised by the split-cam rollers 10 of the invention and a dwell or accumulating phase wherein the propelling member 52a is lowered by the split-cam rollers 10 of the invention causing the associated conveyor rollers 106 to cease further rotation. A variety of types of sensor and stop actuating mechanisms can be utilizedQthere skill sufficient skil in this art to provide the various operational functions performed automatically or manually.

FIGS. 10-12 illustrate an alternative conveyor embodiment in which the application of this invention is directed to a conveyor 130 in which the belt or propelling member 50b is mounted substantially at the conveyor surface. Belt 50b as such, makes direct physical contact with the articles E, rather than contacting driving rollers which, in turn, transport the articles as illustrated in FIGS. 7-9. The belt 50b thus moves in the direction of arrow F in this embodiment which is opposite that of belt 500 in the embodiment of FIGS. 79. The construction of this conveyor is quite similar to that of the conveyor illustrated in FIGS. 79 except that instead of rollers 106 extending the entire width of the conveyor track, two outer tracks of rollers of diminished length, namely rollers 106a and 1061; are provided, each group of rollers 106a and 1061; being arranged in spaced relationship along the conveyor and in a common plane to form a conveying surface. The sets of rollers 106a and 10Gb are spaced transversely forming a medial lane 131 in which the continuously driven belts 50b is positioned.

- Referring to FIG. 11, belt 501) in cooperation with split-cam rollers 10 of the invention is positionable between a raised article contacting and propelling position as illustrated in the left fragmentized portion of FIG. 11 when the split-cam rollers 10b are rotating to raise propelling member 50b and a lowered position out of contact with the articles supported on the conveyor rollers 106a and 10Gb when a stop mechanism has been inserted in front of the associated stop pins 36 of each split-cam roller 10b so that the portions of least radius of rollers 12a, 12b 14 and 16 are up so that propelling member 50b is lowered. The operation of cam rollers 10b is identical to that of rollers 10 described previously except that the position of slot 42 and pin 36 is reversed since the direction of rotation is reversed. Thus, the cam roller 10 is arranged for counterclockwise rotation while roller 10b is arranged for clockwise rotation.

A stop slide 132 is mounted beneath rollers 10 having a plurality of raised stops 134 movable longitudinally in similar fashion to stop slides 112, 112a, 112b, etc., described in the embodiment in FIGS. 79. Stop slides 132 are connected to one or more rocker arms 136 which are pivotal about their lower ends 138 about shaft 140 (FIG. 11). The rocker arm is attached at its upper end to sensor roller 142 and intermediate each end to slide 133 by a pin 14.

The principle of operation of conveyor 130 illustrated in FIGS. 10-12 is the same as that previously described in the embodiments of FIGS. 79, the essential difference being that'the propelling member 50b in the embodiment of FIGS. 3-12 frictionally engages the articles themselves to propel them along their support rollers 106a and l06b.

Although but two conveyor embodiments have been shown and described in detail, it will be obvious to those having ordinary skill in this art that the details and construction of this particular embodiment may be modified ina great many ways without departing from the unique concepts presented. It is therefore intended that the invention is limited only bythe scope of the appended claims rather than by particular details of construction shown, except as specifically stated in the claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A cam roller means for supporting a propelling member in both a raised and lowered position comprising first and second eccentric rollers mounted coaxially, and rotatable relative to each other between a lowered position wherein the portions of least radius of said rollers are in phase with each other and supporting said propelling member in its lowered position and a raised position wherein the portions of least radius of said rollers are out of phase with each other forming a circular roller means supporting said propelling memher in its raised position.

2. The roller means according to claim 1 wherein said rollers are stationary in said lowered position and rotating jointly in said raised position.

3. The roller means according to claim 1 wherein said roller means further includes a stop actuated by a keeper movable into and out of engagement with said stop to select the positioning of said rollers in one of said raised or lowered positions.

4. The roller means according to claim 3 wherein said propelling member is a continuously driven belt engaged with at least one of said rollers urging said rollers to move between said raised and lowered positions.

5. The roller means according to claim 4 wherein said first roller has an annular slot, said belt has 21 depending ridge movable in said slot for guiding said belt over said first roller.

6. The roller means according to claim 5 wherein said annular slot has a depth greater than said ridge, said stop being a pin extending laterally through said first roller in said greater depth portion, the opposite ends of said pin extending beyond said first roller for interference with said second roller, said second roller including a circumferential opening extending less than 360, said pin extending through said opening and engageable with each end of said opening to selectively lock said rollers into one of said raised or lowered positrons.

7. The roller means according to claim 6 wherein said keeper has a finger moveable radially relative to said first roller, said finger being movable into said slot for interference with said pin to stop in sequence said first and second rollers.

8. The roller means according to claim 6 wherein said opening extends approximately 180 so that said second roller in said raised position is approximately diametrically out of phase with said first roller.

9. The roller means according to claim 3 wherein a plurality of roller means are positioned beneath said propelling means, said propelling means causing article movement along a conveyor, said keeper being movable into stopping interference with a discrete number of adjacent roller means to cause article accumulation at selected locations along said conveyor.

10. The roller means according to claim 9 wherein said keeper is actuated by a sensor responsive to article movement along said conveyor.

11. The roller means according to claim 1 wherein said portions of least radius are substantially similar and extend less than 180 circumferentially.

12. The roller means according to claim 11 wherein the radius of the portion of least radius of said first roller is greater than that of said second roller whereby said second roller is disengaged from said propelling member when in said lowered position.

13. The roller means according to claim 1 wherein said second roller is counter weighted toward said lower position and said first roller is counter weighted toward said lift position.

14. An eccentric split-cam roller means for supporting a propelling member in both raised and lowered positions comprising: a pair of coaxially adjacent rollers eccentric in cross section and rotatable relative each other into a first position wherein the portions of least radius are in phase with each other and a second position wherein the portions of least radius are out of phase with each other; and a stop on said cam means for selective engagement with a keeper movable into and out of engagement with said stop, said stop when engaged with said keeper preventing further rotation of said rollers causing said rollers to dwell in said first position with said portions of least radius engaging said propelling member thereby lowering said propelling member, said stop when not engaged with said keeper allowing said rollers to be rotated by said propelling member relative to each other into said second position, whereupon said rollers rotate jointly together forming a circular roller means lifting said propeller member.

15. The roller means according to claim 14 wherein one of said rollers includes a stop pin positioned laterally and extending beyond said one roller, the other of said rollers including a circumferential slot through which said pin extends, the length of said circumferential slot being less than 360 whereby said pin engages one or the other ends of said circumferential slot to lock said rollers into one of said two positions.

16. The roller means according to claim 15 wherein said circumferential slot extends approximately 180 so that said rollers in said second position are approximately diametrically out of phase with each other.

17. The roller means according to claim 15 wherein the radial magnitude of the eccentric portion of said one roller is greater than the radial magnitude of the eccentric portion of the other of said rollers so that said propelling member is disengaged from the other of said rollers when said roller means is in said first position.

18. The roller means according to claim 14 wherein said portions of least radius extend less than one-half the circumference.

19. The roller means according to claim 14 wherein one of said rollers include a bias weight which urges said one roller toward said first position and the other of said rollers includes a bias weight which urges said one roller toward said second position when said roller means are free of influence from said propelling member.

20. The roller means according to claim 14 wherein a plurality of roller means are positioned beneath said propelling means, said propelling means causing article movement along a conveyor, said keeper being movable into stopping interference with a discrete number of adjacent roller means to cause article accumulation at selected locations along said conveyor.

21. The roller means according to claim 20 wherein said keeper is actuated by a sensor to article movement along said conveyor.

22. Means for supporting and controlling the position of a conveyor propelling member, said means having a first eccentric roller provided with a flattened portion of least radius, said means characterized by a second eccentric roller provided with a flattened portion of least radius, an element coaxially mounting said first and second rollers for rotation independently of each other, said rollers, with their flattened portions are in phase forming an eccentric support for said propelling member holding it constantly in one position and when said portions are out of phase forming circular support for said propelling member holding it constantly in a second position spaced from said first position.

23. Means as described in claim 22 wherein the radius of said flattened portion of one of said rollers is greater than the radius of the flattened portion of the other of said rollers whereby said propelling member engages only one of said rollers when the flattened portions of said rollers are in phase.

24. Means as described in claim 23 wherein a stop is provided on one of said rollers and a lost motion catch is provided on the other thereof said catch having a pair of spaced abutments, one abutment engaging said stop when the flattened portions of said rollers are in phase and the other abutment engaging said stop when said flattened portions are out of phase.

25. Means as described in claim 24 wherein said lost motion catch is an arcuate slot and said abutments are the ends thereof.

26. The roller means according to claim 1 wherein a third roller is coaxially mounted with said first and second rollers, said third roller corresponding dimensionally to said second roller and rotating jointly therewith, said first roller being positioned intermediate said second and third rollers.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 354 57 DATED December 17, 1974 INVENTOR(S) Clyde L. Bowman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 4;

After "(Figs. 1-3" insert Column 6, line 17;

"a" should be an Column 7, line 1;

"skill sufficient skil" should be being sufficient skill Column 7, line 24;

"belts" should be, belt ;v

Column 8, line 45;

"moveable" should be movable and Column 10, line 23;

"with" should be when Signed-and sealed this 10th day of June 1975.

(SEAL) Attest:

"c. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. A cam roller means for supporting a propelling member in both a raised and lowered position comprising first and second eccentric rollers mounted coaxially, and rotatable relative to each other between a lowered position wherein the portions of least radius of said rollers are in phase with each other and supporting said propelling member in its lowered position and a raised position wherein the portions of least radius of said rollers are out of phase with each other forming a circular roller means supporting said propelling member in its raised position.
 2. The roller means according to claim 1 wherein said rollers are stationary in said lowered position and rotating jointly in said raised position.
 3. The roller means according to claim 1 wherein said roller means further includes a stop actuated by a keeper movable into and out of engagement with said stop to select the positioning of said rollers in one of said raised or lowered positions.
 4. The roller means according to claim 3 wherein said propelling member is a continuously driven belt engaged with at least one of said rollers urging said rollers to move between said raised and lowered positions.
 5. The roller means according to claim 4 wherein said first roller has an annular slot, said belt has a depending ridge movable in said slot for guiding said belt over said first roller.
 6. The roller means according to claim 5 wherein said annular slot has a depth greater than said ridge, said stop being a pin extending laterally through said first roller in said greater depth portion, the opposite ends of said pin extending beyond said first roller for interference with said second roller, said second roller including a circumferential opening extending less than 360*, said pin extending through said opening and engageable with each end of said opening to selectively lock said rollers into one of said raised or lowered positions.
 7. The roller means according to claim 6 wherein said keeper has a finger moveable radially relative to said first roller, said finger being movable into said slot for interference with said pin to stop in sequence said first and second rollers.
 8. The roller means according to claim 6 wherein said opening extends approximately 180* so that said second roller in said raised position is approximately diametrically out of phase with said first roller.
 9. The roller means according to claim 3 wherein a plurality of roller means are positioned beneath said propelling means, said propelling means causing article movement along a conveyor, said keeper being movable into stopping interference with a discrete number of adjacent roller means to cause article accumulation at selected locations along said conveyor.
 10. The roller means according to claim 9 wherein said keeper is actuated by a sensor responsive to article movement along said conveyor.
 11. The roller means according to claim 1 wherein said portions of least radius are substantially similar and extend less than 180* circumferentially.
 12. The roller means according to claim 11 wherein the radius of the portion of least radius of said first roller is greater than that of said second roller whereby said second roller is disengaged from said propelling member when in said lowered position.
 13. The roller means according to claim 1 wherein said second roller is counter weighted toward said lower position and said first roller is counter weighted toward said lift position.
 14. An eccentric split-cam roller means for supporting a propelling member in both raised and lowered positions comprising: a pair of coaxially adjacent rollers eccentric in cross section and rotatable relative each other into a first position wherein the portions of least radius are in phase with each other and a second position wherein the portions of least radius are out of phase with each other; and a stop on said cam means for selective engagement with a keeper movable into and out of engagement with said stop, said stop when engaged with said keeper preventing further rotation of said rollers causing said rollers to dwell in said first position with said portions of least radius engaging said propelling member thereby lowering said propelling member, said stop when not engaged with said keeper allowing said rollers to be rotated by said propelling member relative to each other into said second position, whereupon said rollers rotate jointly together forming a circular roller means lifting said propeller member.
 15. The roller means according to claim 14 wherein one of said rollers includes a stop pin positioned laterally and extending beyond said one roller, the other of said rollers including a circumferential slot through which said pin extends, the length of said circumferential slot being less than 360* whereby said pin engages one or the other ends of said circumferential slot to lock said rollers into one of said two positions.
 16. The roller means according to claim 15 wherein said circumferential slot extends approximately 180* so that said rollers in said second position are approximately diametrically out of phase with each other.
 17. The roller means according to claim 15 wherein the radial magnitude of the eccentric portion of said one roller is greater than the radial magnitude of the eccentric portion of the other of said rollers so that said propelling member is disengaged from the other of said rollers when said roller means is in said first position.
 18. The roller means according to claim 14 wherein said portions of least radius extend less than oNe-half the circumference.
 19. The roller means according to claim 14 wherein one of said rollers include a bias weight which urges said one roller toward said first position and the other of said rollers includes a bias weight which urges said one roller toward said second position when said roller means are free of influence from said propelling member.
 20. The roller means according to claim 14 wherein a plurality of roller means are positioned beneath said propelling means, said propelling means causing article movement along a conveyor, said keeper being movable into stopping interference with a discrete number of adjacent roller means to cause article accumulation at selected locations along said conveyor.
 21. The roller means according to claim 20 wherein said keeper is actuated by a sensor to article movement along said conveyor.
 22. Means for supporting and controlling the position of a conveyor propelling member, said means having a first eccentric roller provided with a flattened portion of least radius, said means characterized by a second eccentric roller provided with a flattened portion of least radius, an element coaxially mounting said first and second rollers for rotation independently of each other, said rollers, with their flattened portions are in phase forming an eccentric support for said propelling member holding it constantly in one position and when said portions are out of phase forming circular support for said propelling member holding it constantly in a second position spaced from said first position.
 23. Means as described in claim 22 wherein the radius of said flattened portion of one of said rollers is greater than the radius of the flattened portion of the other of said rollers whereby said propelling member engages only one of said rollers when the flattened portions of said rollers are in phase.
 24. Means as described in claim 23 wherein a stop is provided on one of said rollers and a lost motion catch is provided on the other thereof said catch having a pair of spaced abutments, one abutment engaging said stop when the flattened portions of said rollers are in phase and the other abutment engaging said stop when said flattened portions are out of phase.
 25. Means as described in claim 24 wherein said lost motion catch is an arcuate slot and said abutments are the ends thereof.
 26. The roller means according to claim 1 wherein a third roller is coaxially mounted with said first and second rollers, said third roller corresponding dimensionally to said second roller and rotating jointly therewith, said first roller being positioned intermediate said second and third rollers. 